IEEE sections 802.11, 802.11(a), 802.11(b), 802.11(g), 802.11(h), 802.11(n), 802.16, 802.20, which are incorporated herein by reference in their entirety, define ways for configuring wireless networks and network devices. According to these standards, a wireless Ethernet network device may operate in an ad-hoc mode or an infrastructure mode.
Referring now to FIG. 1, in the ad-hoc mode, each client station 10-1, 10-2, . . . , and 10-N (collectively client stations 10) communicates directly with other client stations without requiring an access point (AP). Referring now to FIG. 2, in the infrastructure mode, each client station 20-1, 20-2, . . . , and 20-M (collectively client stations 20) communicates with other client stations through an AP 24. The AP 24 may provide a connection to a network 26, a server 28, and for the Internet 30.
In the infrastructure mode, the AP 24 and the client stations 20 that use the AP 24 constitute a basic service set (BSS). A wireless network can comprise multiple BSS's. Each BSS is identified by a unique identifier for the AP in the BSS, called a BSSID. Typically, the AP transmits a beacon to inform the client stations in the BSS that the AP is ready to communicate with the client stations. The beacon includes the BSSID for the AP. The client stations in the BSS, in turn, communicate with the AP using the BSSID.
Referring nosy to FIG. 3, a network device such as an AP or a client station may be implemented using a system on chip (SOC) circuit 40 and/or individual components. The SOC circuit 40 generally includes one or more processors 42, a medium access controller (MAC) device 44, a base band processor (BBP) 46, and a host interface such as a peripheral component interface (PCI) (not shown). Additionally, the SOC circuit 40 may include a radio frequency (RF) transceiver 48, or the transceiver may be located externally.
Most modern wireless networks comprise different types of network devices as client stations. For example, in the wireless network shown in FIG. 2, the client station 20-1 may be a video device such as a high definition TV that may be utilized in applications such as video-conferencing. The client station 20-2 may be an audio device. Additionally, the client station 20-M may be a laptop computer that may be used to transfer files, exchange emails etc.
Different types of client stations may utilize different applications running on the network and may generate different data streams. For example, the client station 20-1 may generate data streams comprising video and audio data. The client station 20-2 may generate data streams comprising audio data. The client station 20-M may generate data streams comprising text files, etc. Thus, different types of data streams may concurrently flow through the network.
Network users generally expect their individual applications to run smoothly regardless of other applications that concurrently utilize the network. Networks, however, have finite resources. For example, bandwidth of a network is limited. Therefore, networks typically service data streams of different applications at different priority levels to optimize network resources and deliver optimum performance to network users. For example, a network may service data streams of a video-conferencing application at a higher priority than data streams of an audio application or an email application.
Additionally employs admission control mechanisms to ensure that resources are not over-stretched. Admission control mechanisms allow applications to join the network only when available resources are adequate to optimally run the applications, meet the Quality of Service (QoS) requirements
The priority given to data streams, however, should be such that a data stream given a low priority is not substantially delayed or entirely lost. Quality of service (QOS) refers to an ability of a network to provide a particular level of service to a selected data stream. IEEE section 802.11e defines QOS mechanisms for wireless networks and is incorporated herein by reference in its entirety.
QOS mechanisms in wireless networks generally comprise scheduling mechanisms and signaling mechanisms that an access point uses to service applications used by client stations. Scheduling mechanisms ensure that different data streams in a network receive adequate priority to link to the network. Scheduling mechanisms are incorporated along with complimentary admission control mechanisms. Signaling mechanisms notify the network of a priority and characteristics of a data stream. Signaling mechanisms typically use protocols that request and establish a link to the network for a data stream.
For example, a signaling mechanism called resource reservation protocol (RSVP) enables an application to request the network for a specific level of service for a data stream and to dynamically service a part of network bandwidth for the data stream. Thus, the client station 20-1 may request the AP 24 a priority_1 for data streams of the video-conferencing application. The client station 20-2 may request the AP 24 a priority_2 for data streams of the audio application, where priority_2 is a lower priority level than priority_1, etc.
Signaling mechanisms, however, burden network traffic. Additionally, signaling mechanisms use protocols that are preconfigured based on factors such as network resources, user demand, etc. Thus, signaling mechanisms lack flexibility and scalability. Additionally, signaling mechanisms need end-to-end support. That is, all devices need to implement the same signaling stack. The disparate nature of devices, however, precludes wide-spread adaptation of a single signaling protocol.
Scheduling of data streams in wireless networks may be improved by pre-configuring client stations with pre-set stream descriptors and service priority levels. The service priority levels can be pre-set based on a class of service a client station requires. The traffic characteristics of data streams can be set based on the perceived general behavior of network connections.
An AP may decipher a service priority level and stream descriptors from a data stream received from the client station. The AP can service the data stream according to that priority level and stream descriptors. This scheme, however may be problematic since different original equipment manufacturers (OEM's) may assign service priority levels and stream descriptors to network devices (client stations) differently.